Radiation-increasing device and system



2 Sheets-Sheet l C. E WAMBO RADIATION-INCREASING DEVICE AND SYSTEM Dec. 22, 1964 Filed Oct. 19, 1961 INVENTOR. CHA 21.55 E. WA M 50,

BY M *M TOR N E (5.

Dec. 22, 1964 c. E. WAMBO RADIATION-INCREASING DEVICE AND SYSTEM 2 Sheets-Sheet 2 Filed Oct. 19, 1961 INVENTOR. (11,421.55 E. WAnao, BY

ATTOR NEY8.

i of the wire.

terial and preferably is principally composed of alumi- United States Patent 3,162,244 RADIATIGN-ENCREASING DEVKIE AND SYSTEM fiharlcs E. Wamho, Wayne County, Ind, assignor to Products, incorporated, Richmond, End, a corporation of Indiana Filed Oct. 19, 196i, der. No. 146,293 2 Claims. (til. 165-184) This invention relates to a heating system such as a steam or hot-water system of the type used in greenhouses, and to a device for application to selected portions of radiation pipe for locally increasing the heat radiation therefrom.

Greenhouse heating systems commonly employ heat radiators in the form of simple pipe running in long lengths through large areas. In the actual operation of greenhouses, however, it is often desirable to increase the heat output in the localized areas which may be portions of the areas heated by the same continuous radiation pipe assembly. Previously, an increase in heat to such a partial area could only be accomplished by revising the entire pipe radiation assembly, at considerable cost and trouble.

It is the object of the present invention to provide a simple radiation-increasing element and modification which can be applied to existing radiation pipe to increase the heat transfer therefrom. The modification element preferably takes the form of a coil spring unit, wound of heat-conductive metal such as aluminum, in units of convenient length for handling. These are wrapped in helical turns about the outer surface of the pipe from which it is desired to increase heat radiation. The coil spring unit is of sufficient resilience, and is Wound on the pipe with suflicient tension, to engage the surface of the pipe snugly and in firm contact. The ends of the coil spring unit are secured in place by simple clamps fastened about the pipe, and adjacent ends of successive units may be secured by the same clamp.

One of the purposes of the invention is to provide radia- Lion-increasing units which can be applied to existing pipes, often for temporary use, and which can be readily applied and removed by the greenhouse operator in accordance with the changing requirements of his varied uses of diiferent greenhouse areas. To meet this purpose, it is evident that the coil spring units must be removably secured in place and that the coils of the spring unit can not be soldered, welded or otherwise joined to the pipe, and on the contrary, must lie in un-joined face to face contact with the surface of the pipe. Under these conditions, if a significant increase in radiation is to be obtained, I have found that special provisions must be made, in accordance with which the coil spring unit is .width which is substantially more than one-half the diameter of the wire and desirably a width which is of the order of /3 to if; or more of the wire diameter. The

wire diameter is desirably of the order of from onefi fteenth to one-tenth the diameter of the pipe. Ina preferred embodiment the coil is wound from round wire which is flattened as it is wound to form a flat outer face of a width substantially equal to the final flattened thickness of the wire in a direction radially of coil. The coil unit is preferably wound as a tight or closely wound spring, that is, with the coils touching or close together, and the unit, before and during application, ,is stretched to space the coils by spaces of theorder of the thickness The wire used is of heat conductive manurn, both for its heat conductivity and its cold-working properties.

The coil unit is desirably wrapped about the pipe in a helix of the same hand as the coil itself, and with the wrap at a pitch of the order of from 2 to 3 times the diameter of'the pipe. The diameter of the coil is desirably somewhat smaller than the pipe itself, preferably of the order of one-half the diameter of the pipe on which it is used. For example, a coil unit wound from .125 inch round wire, flattened to provide a flat outer face about .105 inch wide, and wound to form a coil of inside diameter is especially suited for use on standard 1-inch pipe, and may also be used on I la-inch and 1 /2- inch pipethese being sizes which are commonly used for heat radiation.

Other objects and features of the invention will be evident from the embodiment shown in the accompanying drawings and described below.

In the drawings,

FIG. 1 is a diagrammatic sectional view of a greenhouse heating system to which my invention is applied;

FIG. 2 is a side elevation of a length of radiation pipe to which a radiation-increasing coil unit has been applied in accordance with the invention;

PEG. 3 is a coil unit in accordance with the invention,

the coil being in tight-wound condition as originally formed;

FIG. 4 is fragmentary section taken radially along one turn of the pitch line on which the coil unit is wound about a pipe, as on the line 4-4 of FIG. 2, showing the coil unit in section on its diameter;

FIG. 5 is a fragmentary sectional view showing the cross section of a coil of the unit, in contact with the wall of a pipe.

The greenhouse is shown in FIG. 1 comprises a series of bays 12, M, 16 and 1%, open to each other but-providing separate growing areas in which the same or different operations may be carried out. The greenhouse is heated by a boiler 2d,.which is shown as a steam boiler but which may be a hot Water boiler. This is connected by a feed pipe 22 to a header 24, which is connected through individual valves 26 to a plurality of heating loops 28. Each heating loop 28 consists of a series of radiation pipes joined end to end, and extends lengthwise through the entire length of the building, to heat all of the bays 12, 14-, 16 and 18. A return or condensate line 30 leads back to the boiler 26.

In the operation of the greenhouse lit, it may be assumed that at certain periods of time it is desirable to increase the heat in the bays 16 and 18 while'it is undesirable to do so in the bays 12 and 14 heated by the same heating loop 2-8. To meet these different requirements, the pipe lengths 29 in the bays Hand 18 are wrapped with radiationdncreasing coil spring units to increase the radiation from these parts of the loop 28 while leaving the radiation rate the same over the lengths of pipe 31 in the bays 1?; and 14. As shown, each length of pipe 29 carries five coil spring units 34 wound ina right hand helix about the pipe and connected at the ends by clamps 36.

The radiation-increasing coil spring units 34 are more fully shown in FIGS. 2 to 5. Preferably, each unit is originally formed as a tight-wound helical coil of right hand lay, as shown in FIG. 3. This is wound from heatconductive' aluminum wire of round cross-section, and in the winding the wire is deformed and flattened to the cross sectional shape shown in FIG. 5. This provides a substantially flat wide external face 33, rounded sides 4% and an inner flattened or knurled face 4.2. In a preferred embodiment, the: wire used was 0.125 inch in diameter,

- and was flattened about 20% during the forming and winding to a radial thickness between the faces 38 and from the pipe.

- a s 42 to approximately 0.105 inch, and the fiat face 38 formed on the outer periphery of each coil was approximately 0.105 inch wide-a width of the same order as the.

radial thickness of the wire, The coil unit shown was wound to a A3 inch inside diameter and with 385 turns or coils; Eyes 43 were formed at each end, and engaged in wire clamps 36 for securing the unit to the pipe. This formed a solid-wound coil spring unit approximately 4 feet long in its-original state, in which it is conveniently handled and sold. v

Before application, the -4-foot coil spring unit 34 is de sirably stretched to impart uniform spacing between its several calls and to bring it to an unstressed length more convenient for application to the pipe, butfto leaveit sufficiently short that it Will lye-definitely stressedduring ap:

plica'tion. With the resilient aluminum wire which I have used, the original l-foot coil unit is initially stretched to a length-of 7 or '8 feet, andwill'r-ebound to a length of approximately 5 or 6 feet. Itis then applied to the pipe by first securing one end byrneans of its clamp 36'3Ild then wrapping the elongated coil, under manual tension, 1

order of 125%, While on l /z-inch pipe (1.9 O.D.) it produced an increase of nearly'100%. These are'efl ective and practical increases for providing the heat variations required in greenhouse operation.

"The particular form and-features of the units 34 con tribute materially to their operation. .By way of comparison with the test results mentioned above, correspond ing tests Were made using-coils Wound from smaller wire to form approximately eleven turns about the pipe in a pipe length of approximately 4 feet, This provides about 33 coils per turn about the pipe which stand in the relationship shown in FIG. 4. The external flat face 38 of;

each coil lies in firm face-'to-face contact with the surface 44 of the pipe, and the several coils are spaced from each other at the pipe :surface'by distances of the order of the wire width, and stand in open diverging relation outward As indicated in FIG. 5,1116 fiat outer face ss'or each coil of the unit 34 lies in face-to-face contact with the by the tension of the coil spring unit.

creases the radiation which occurs from'the length of pipe on which the unit is Wound. In the heating system shown in FIG. 1, the-lengths of pipe 29in the greenhouse bays '16 and 18, are given substantially greater heat radiation capacity by reason "of the presence of the heat radiation units 34 wrapped about them. I Asa result, the heat supplied to the bays 16 and 18 is substantially increased while the heat supplied to the bays .12 and 14, Where the pipes 31 are left bare, remains the same.

- Tihe %-inch coil unit shown and described is especially adapted for application to standard 1-inch pipe; Such pipe has an outside diameter of 1.315 inches so that the.

diameter of the coil unit is approximately one-half th'at of the pipe. In tests on 1-inch pipe, the %'-inch unit exterior surface 44 of the pipe 19, and is held thereagainstm This gives good heat-conductivity between the pipe and the Wire, so that,

"35 the radiation-increasing coil unit '34 substantially in-" 1,265,903, I so of round cross-section and without the outer flattened face, and these produced a,,;radiation increase of less than 20%.

' I claim as my inventionr 1. Heating apparatus adapted for use in greenhouses and the like, comprising a radiation pipe of a size of the order of 1-inch to l /z-inch pipe, and a radiation-increasing element on said pipe, said element comprising a helical coil formed of a multiplicity of turns of a continuous length of heat-conductive resilient wire, wrapped helically in a plurality of turns about the surface of a length of said pipe, said wire-being of a size having a diameter of the order of one-fifteenth 'to one-tenth the diameter of the 'pipe,-: having a continuous flat face at theouter periphery of the coil to make 'face-to-tace contact with the pipe surface at each turn of the coil, the width ofthe flat face being at least two thirds of the wire diameter, and also having a flattened .face at the inner periphery of the coil, I the coil being a substantially round coil of a diameter of 17116 order of one half the diameter of said pipe 7 and less than the fulldiameter of said pipe, and being wound about thepipe ina helix having a pitch of the orderof two to three times the :diameter of said pipe, 7 t the successive turns of the coil being pressed by the resilience of the coil into firmcontact with the :pipe at'said fiat outer faces thereof and-being spaced from each other ,bydistances of the order of the wire diameter, 7 p 1 d ns releasably securing the ends of the coil in fixed poist-ions on the pipe.

2. Heating apparatus; as defined in claim 1 in which the flattened face at the inner periphery of the coil is knurledQ y, a

i References Citedin :the file of this patent UNITED STATES PATENTS 636,615 Great Britain May 3, 1950 Great Britain .Oct. 17,, 1951 

1. HEATING APPARATUS ADAPTED FOR USE IN GREENHOUSES AND THE LIKE, COMPRISING A RADIATION PIPE OF A SIZE OF THE ORDER OF 1-INCH TO 1 1/2-INCH PIPE, AND A RADIATION-INCREASING ELEMENT ON SAID PIPE, SAID ELEMENT COMPRISING A HELICAL COIL FORMED OF A MULTIPLICITY OF TURNS OF A CONTINUOUS LENGTH OF HEAT-CONDUCTIVE RESILIENT WIRE, WRAPPED HELICALLY IN A PLURALITY OF TURNS ABOUT THE SURFACE OF A LENGTH OF SAID PIPE, SAID WIRE BEING OF A SIZE HAVING A DIAMETER OF THE ORDER OF ONE-FIFTEENTH TO ONE-TENTH THE DIAMETER OF THE PIPE, HAVING A CONTINUOUS FLAT FACE AT THE OUTER PERIPHERY OF THE COIL TO MAKE FACE-TO FACE CONTACT WITH THE PIPE SURFACE AT EACH TURN OF THE COIL, THE WIDTH OF THE FLAT FACE BEING AT LEAST TWO THIRDS OF THE WIRE DIAMETER, AND ALSO HAVING A FLATTENED FACE AT THE INNER PERIPHERY OF THE COIL, THE COIL BEING A SUBSTANTIALLY ROUND COIL OF A DIAMETER OF THE ORDER OF ONE HALF THE DIAMETER OF SAID PIPE AND LESS THAN THE FULL DIAMETER OF SAID PIPE, AND BEING WOUND ABOUT THE PIPE IN A HELIX HAVING A PITCH OF THE ORDER OF TWO TO THREE TIMES THE DIAMETER OF SAID PIPE, THE SUCCESSIVE TURNS OF THE COIL BEING PRESSED BY THE RESILIENCE OF THE COIL INTO FIRM CONTACT WITH THE PIPE AT SAID FLAT OUTER FACES THEREOF AND BEING SPACED FROM EACH OTHER BY DISTANCES OF THE ORDER OF THE WIRE DIAMETER, AND MEANS RELEASABLY SECURING THE ENDS OF THE COIL IN FIXED POSITIONS ON THE PIPE. 